Redwood Falls is taking a major step forward with a new wastewater treatment facility upgrade to address current needs and comply with stricter environmental regulations. Previously expanded in 1988, the city’s current system is running at full capacity and can no longer support future growth without improvements in phosphorus treatment and reduction of ground water infiltration and inflow.
Why the Upgrade is Needed
The city’s wastewater treatment facilities are reaching their limits. Recent heavy rains have pushed the system past its permitted flow, risking pond overflows. In addition, new phosphorus limits require significant upgrades to meet water quality standards. The city’s current in-pond treatments and phosphorus trading agreements are no longer sufficient to keep up with these stricter requirements imposed by the US Environmental Protection Agency (EPA) and the Minnesota Pollution Control Agency (MPCA).
Two Paths Forward
To solve these challenges, the Redwood Falls City Council considered two options:
- Tertiary Treatment with Disk Filters: The most cost-effective option at $8-10 million, this solution upgrades the existing system with disk filters and aeration improvements. It will meet new phosphorus limits at current design, but won’t provide enough capacity for future growth without reducing the current inflow of groundwater.
- New Mechanical Treatment Facility: This more expensive option would build an entirely new facility at a cost of $30-70 million. While it offers additional capacity for future growth, it comes with a higher price tag and increased operational costs.
The Recommended Solution
The City Council approved moving forward with the tertiary disk filter option, which provides the most cost-effective and immediate solution to meet regulatory requirements. In addition, the City was able to obtain a $7 million dollar grant from the State of Minnesota with low interest financing for the remainder of the project cost. This upgrade, along with efforts to reduce the amount of rainwater and groundwater entering the system, will help minimize overflow risks. This option is anticipated to meet requirements for a minimum of 15 years or until EPA and MPCA pass down new future requirements.
Project Timeline
The Wastewater Treatment Facility Renovation Project was put out for bid in March 2024 and was awarded in April to Gridor Construction Inc. of Buffalo, MN. Construction started this mid-summer and this multiyear project is expected to be online by December 2025.
A Future-Ready Wastewater System
This upgrade is essential for maintaining the City’s Major Facilities Permit with the EPA and to remain in compliance with environmental standards. By addressing inflow and infiltration, meeting new phosphorus limits, and restoring treatment capacity, Redwood Falls is positioning itself for a sustainable future, ensuring that the community continues to thrive while protecting local water resources.